Phytoplankton community adaptation to changing light levels in the southern Beaufort Sea, Canadian Arctic

• DOI: 10.1016/j.ecss.2009.02.024
• Publication Date: 2009-03-04T10:14:12Z
• Authors: Atsushi Matsuoka; Pierre Larouche; Michel Poulin; Warwick Vincent; Hiroshi Hattori
• Keywords: 0106 biological sciences; 550; 13. Climate action; 14. Life underwater; [SDU.STU.OC] Sciences of the Universe [physics]/Earth Sciences/Oceanography; 01 natural sciences; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography

Abstract The chlorophyll a specific absorption coefficient of phytoplankton, a φ ∗ ( λ ) is an important parameter to determine for primary production models and for the estimation of phytoplankton physiological condition. Knowledge of this parameter at high latitudes where nutrient rich cold water submitted to low incident light is a common environment is almost nonexistent. To address this issue, we investigated the light absorption properties of phytoplankton as a function of irradiance, temperature, and nutrients using a large data set in the southern Beaufort Sea during the open water to ice cover transition period. The a φ ∗ ( λ ) tended to increase from autumn when open water still existed to early winter when sea ice cover was formed, resulting from a biological selection of smaller-size phytoplankton more efficient to absorb light. There was no significant correlation between a φ ∗ ( λ ) and irradiance or temperature for both seasons. However, a φ ∗ ( λ ) showed a significant positive correlation with NO 3 + NO 2 . Implications of the results for phytoplankton community adaptation to changing light levels are discussed.